One of the main objectives of Lean Construction is the generation of value for all building project stakeholders. Based on this approach, value can be generated by reducing the cost of products or services delivered and/or by improving the performance or satisfaction of participants involved in the project. The Target Value Design (TVD) is a Lean tool that enables the design to meet such an important purpose. The objective of this article is to present a protocol for the implementation of the TVD during the Project Definition and the Lean Design in building projects with a particular emphasis on office and housing construction. For such purpose, a Value Stream Mapping is presented including the most important areas intervening in a building project. Through the use of flow charts, the various stages and activities are shown from the point in which the project idea arises up to the stage where plans and technical specifications are submitted. These charts display the moments when the best opportunities take place to add value by eliminating waste, reducing lead time, optimizing costs, and/or improving the quality of products. Along with the charts, a cost structure following the same sequence as that of the design process is also shown, which allows economic valuations at any stage of process development. This prevents the frequent need for re-work that results from having such cost available just at the end of the whole design process. The contribution of this study is to provide the project design team with this protocol together with its corresponding cost structure. We are sure this will be useful for promoting the TVD implementation during the Project Definition and Lean Design phases, which may be subject to improvements or customized for each project case.